Well straight away, the most noticeable thing is how you seem to make the arms thinner and thinner as you get towards the hand, thereby making the hand smaller than it should be. Time to start working on volume, attached a page from Loomis to illustrate what I mean.

Technique-wise these are fine, and you have some feeling for the body mass, but... your lay-in is too often out of proportion or stiff. The problems are not with the finish or anatomical details, they are with the most basic structure.

Recommendation: stop drawing in detail for a while, switch to gesture drawing, learn to draw the figure loosely but with accurate mass, foreshortening and proportions.

Beautiful lines and shading. Now proportions like suggested! With every drawing, but specially those with foreshortening, don't trust your judgment of how long or wide things are. Do some sight measuring, and draw from life as much as possible.

Updated with More Material!

I did another round of sketches. I feel like these are getting better. I tried to focus on proportions as much as possible as well as weight and the forces acting on the figure. More feedback please (if it's not too much trouble):